A clutch for use on a motorcycle is known. Japanese Patent Publication Laid-open No. 2005-325993, for example discloses a vehicle clutch that includes a clutch outer connected to an input member, a clutch inner that is coupled to an output member and arranged so as to be relatively rotatable within the clutch outer, a first friction plate spline-engaged to the clutch outer so as to be slidable in an axial direction, a second friction plate overlaid with the first friction plate spline-engaged with the clutch inner so as to be slidable, a pressed plate provided integrally at the clutch inner so as to face one side of the first and second friction plates, a pressing plate arranged facing the pressed plate sandwiched between the first and second friction plates so as to be capable of moving in an axial direction, a clutch spring urging the pressing plate towards the pressed plate, and clutch actuating members that resists urging force of the clutch spring so as to move the pressing plate to the opposite side to the pressed plate. In this example, thrust that pushes the pressing plate towards the pressed plate is then generated between the clutch inner and the pressing plate when positive torque acts from the pressing plate to the clutch inner.
The spring-load of the clutch spring of the clutch described above is lowered and a clutch disengaging operation load is reduced, which increases the clutch capacity during transmission of positive torque. However, when this clutch is operated in a half-clutch state, it is difficult to perform delicate operations due to an axial pulling force and friction force being generated by the cam mechanism as the amount of positive torque transmitted increases are applied to the pressing plate.
One object of the present invention to provide a vehicle clutch that is capable of a delicate half-clutch operation but also retains the above benefits.